The present invention relates to seating and the like, and in particular to weight actuated height adjustors therefor.
A wide variety of furniture articles, such as tables, seating, and the like, employ an adjustment mechanism to vary the height of a selected portion of the furniture article. For example, in seating, a height adjustor is used to vary the height of the seat above the base, so as to accommodate or adjust the seating for different users and tasks.
Weight actuated height adjustors, such as the device disclosed in U.S. Pat. No. 4,324,382 to Beukema et al., which is assigned to the assignee of the present application, have been used in seating, particularly swivel chairs and tilt back chairs, that are designed for use primarily in office environments. Such weight actuated height adjustors typically engage only when the chair is unoccupied, and adjustment of the seat height is achieved by rotating or swiveling the chair with respect to the base. When the chair is occupied, the height adjustor typically disengages to permit the chair to swivel about the base without affecting the selected seat height.
Heretofore, chairs with weight actuated height adjustors have had a tendency to slowly drop downwardly from their selected height setting. If the user quickly exits the chair with a twisting motion, as can be experienced when the user exits the chair from a forward facing, sitting position at a desk, or other similar work surface, the chair may tend to continue swiveling or rotating after the user's weight is removed from the seat. This additional swiveling motion or "run-on" rotation can cause a slight change in the selected height of the seat.
Furthermore, when the user returns to his or her station, the user sometimes rotates the chair to a selected entry position before the user sits down. This type of action can also result in some slight, unintentional adjustment of the selected seat height.
Over a relatively long period of time, the circumstances outlined above, as well as other similar activities, can cause the chair to continuously move or adjust downwardly, until the chair is so far out of adjustment that it must be readjusted. Such unintentional height adjustment can prove to be rather frustrating, particularly in those situations and tasks where the user continuously moves in and out of the chair. Furthermore, since the unintentional adjustment occurs in very slight increments, the user often does not realize that the chair height needs to be readjusted until it has reached a very uncomfortable position, thereby detracting from the overall comfort of the chair.